Carboplatin as a Radiosensitizer in Treating Childhood Ependymoma

Inclusion Criteria: * Patients must be enrolled before treatment begins. * Patients must be ≥ 12 months and \< 22 years of age at the time of diagnosis. * The target tumors are primary brain non-metastatic (M0) ependymomas tumors. Patients must have histologic verification of an ependymoma at diagnosis. Patients with the following world health organization (WHO) diagnoses will be eligible for this study:Ependymoma (Subtypes: cellular, papillary, clear cell and tanycytic) and Anaplastic Ependymoma * Life expectancy of ≥ 8 weeks. * Newly diagnosed ependymoma and must not have had any prior chemotherapy or radiotherapy. * All patients must have: * A pre-operative MRI scan of the brain with and without contrast. NOTE: CT scans are NOT sufficient for study eligibility since radiation therapy planning and responses will be based on MRI scans only. * Post-operative head MRI scan with and without contrast (preferably within 72 hours post-operatively). * Spinal MRI (T-1 weighted imaging with and without gadolinium) is required within 28 days of surgery if done post-operatively and within 14 days of surgery if done pre-operatively. For posterior fossa tumors, pre-operative MRI scans are preferred because surgically induced inflammation/blood can be difficult to distinguish from tumor. * Lumbar CSF cytology examination obtained between 7 and 31 days following surgery. * Adequate bone marrow function, defined as: * Peripheral absolute neutrophil count (ANC) \>1500/μL * Platelet count ≥ 100,000/μL (transfusion independent) * Hemoglobin ≥ 10.0 gm/dl (may receive RBC transfusions) * Adequate renal function defined as: * Serum creatinine \< 1.5 times the upper limit of normal based on the patient's age, or creatinine clearance greater than 60 ml/min/1.73 m² corrected for age and body surface area. * Adequate liver function defined as: * Total bilirubin \<1.5 x the institutional normal * SGOT (AST) or SGPT (ALT) \<2.5 x institutional normals. * Patients must begin chemoradiotherapy within 56 days of definitive surgery. * All patients and/or their parents or legal guardians must sign a written informed consent * Patients must provide assent as per local IRB guidelines (if applicable). * Patients and/or their families must consent to the mandatory biology studies, including serum Survivin levels, CSF Survivin levels, paraffin-embedded tissue and fresh-frozen tissue when available. * Karnofsky/Lansky scoring greater than 50. * Corticosteroid supportive care is permissible at the clinician's discretion prior to and during chemo-radiotherapy. * Anti-seizure medication support is permitted as necessary and at the treating physician's discretion. Exclusion: * Prior chemotherapy or prior radiotherapy * Patients who are pregnant or breast feeding, or patients (male or female) not employing adequate contraception. Acceptable means of birth control include IUD, oral contraceptive, subdermal implant, a condom with a contraceptive sponge or suppository or abstinence. * Patients who are unable to undergo MR imaging * Patients with evidence of metastatic disease on spine MRI or CSF sampling * Patients with post-operative residual tumor \> 0.5 cm, unless a repeat surgery is performed making the residual tumor less than 1.5 cm². Note: Timing for enrollment and initiation of therapy will begin after second surgery if a repeat surgery is performed.